The concept of Outpatient Parenteral Antibiotic Therapy (OPAT) is relatively new in Asia. This study compared the actual costs and outcomes of care involving OPAT with conventional inpatient-only care at a university hospital in Singapore. Actual costs were obtained for selected patients enrolled in OPAT after 1 January 2005 and these costs were directly compared with those of age-, gender- and diagnosis-matched patients managed as inpatients only prior to the availability of OPAT in the preceding 12 months. Outcomes of patients were also considered. The OPAT and inpatient-only groups comprised 72 and 93 enrollments, respectively. Mean treatment duration for OPAT patients was 42.5 days versus 19 days for those receiving inpatient-only care (P < 0.001). The mean total treatment cost for OPAT and inpatient-only care was US$12 736 and $12 403, respectively (P = 0.706). Mean cost per day for care including an OPAT episode was US$278 versus $457 per day for inpatient-only care (P < 0.001). There was no difference in outcomes between the two groups. OPAT is a viable alternative to inpatient care as it is safe, effective and results in lower daily costs. The trend to longer treatment courses is worthy of further review.